Portable combination flattened cylindrical sander-grinder



Jan. 13, 1970 J. 5 McCAY 3,488,889

PORTABLE COMBINATION FLATTENED CYLINDRICAL SANDER-GRINDER Filed Jan. 23, 1968 2 Sheets-Sheet 1 FIG. 1.

/0 IN VEN TOR.

JOHN s M? 04 v,

ATTOE/VEYS.

PORTABLE COMBINATION FLATTENED CYLINDRICAL SANDER-GRINDER Filed Jan. 23, 1968 J. S. MCCAY Jan. 13, 1910 2 Sheets-Sheet 2 INVENTOR. JOHN s. 04v, 25

ATTOE/VGYS,

3,488,889 PORTABLE COMBINATION FLATTENED CYLINDRICAL SANDER-GRINDER John Stanley McCay, 208 N. 2nd St., Baldwyn, Miss. 38824 Filed Jan. 23, 1968, Ser. No. 699,950 Int. Cl. B2411 21/18 US. Cl. 51-135 6 Claims ABSTRACT OF THE DISCLOSURE A portable sander-grinder including a fixed drive wheel; a driven Wheel movable toward and from said drive wheel; means biasing said driven wheel away from said drive wheel; an abrasive belt passing around both wheels; means for transverse angular adjustment of the axis of the driven wheel relative to the axis of the drive wheel; a work support adjacent said drive wheel and a work support under said belt between said drive wheel and said driven wheel.

It is an object of this invention to provide a portable belt-type abrasive device which will be extremely compact and will permit presentation of the work either against a cylindrical, moving, abrasive surface or against a flat, moving, abrasive surface.

It is a further object of this invention to provide a machine of the type aforesaid in which one belt may be removed and replaced with another belt without physical alteration of the machine.

It is a further object of this invention to provide a machine as aforesaid in which each of the work portions of the abrasive surface is equipped with an easily adjustable tool holder.

It is a further object of this invention to provide a machine as aforesaid in which, by means of a simple adjustment, any belt can be brought into true running alignment between the driving and driven pulleys.

The above and other objects will be made clear from the following detailed description taken in connection with the annexed drawings, in which:

FIGURE 1 is a perspective view of the machine as a whole;

FIGURE 2 is a top plan view of FIGURE 1, with the light holder omitted;

FIGURE 3 is a view partially in section taken on the line 33 of FIGURE 2;

FIGURE 4 is a view partially in section taken on the line 44 of FIGURE 3; and

FIGURE 5 is a perspective view of a handle useable in changing belts.

On a belt-type machine, such as is the subject of this application, the only difference between sanding and grinding is the nature of the abrasive afiixed to the belt. Generally speaking, sanding belts are used on wood while grinding belts are used on metal but so far as the machine is concerned, whether it be used as a sander on wood or a grinder on metal is completely immaterial. Therefore, as used herein, the Word sander" shall include grinder and vice-versa.

Referring now to FIGURE 1, the machine is set up on a portable base member 10, to which is secured a bracket 12 having a horizontal arm 14 spaced above the base and acting as a support for a motor 16. A drive pulley 18 is mounted directly on the motor shaft and has a rim 20 provided with ventilating apertures 22.

At the rear end of the machine a pair of brackets 24 are secured to the base 10 and serve as a mounting for a U-shaped member 26. A lower horizontal leg 28 of the U-shaped member 26 is pivotally supported in the brackets United States Patent 0 ice 24 while an upper parallel leg 30 forms the axle for a driven pulley 32.

A spring 34 is coiled around the leg 28 and has one end 36 hearing on a plate 38 of which the brackets 24 are integral tongues. The opposite end 40 of the spring 34 bears against the leg 30 in such a direction as to bias the pulley 32 away from the drive pulley 18.

An abrasive belt 42 passes around both the pulleys 20 and 32 and is driven thereby. If it is desired to do a grinding job on the belt 42 as it passes around the pulley 20, use is made of a tool holder 44 which is an L-shaped member having one leg 46 passing through a block 48 secured to the bracket 12. An L-headed set screw 50 is threaded into the block 48 and secures the member 44 in any desired position. In FIGURE 1, the member 44 is shown as having its upper L-head 52 swung parallel to and spaced from the belt 42 as it passes over the drive pulley 20 which permits presentation of a Work piece 54 to the belt, as shown in FIGURE 1.

To form a work support and work stop in the flat portion of the belt 42, the following is provided: a channel iron is bent at its lower end to provide a horizontal leg 62 which is bolted at 64 (FIGURES 3 and 4) to the base 10. At its upper end the channel 60 is bolted through a spacing washer 66 (FIGURE 2) to a work support 68 which has a laterally projecting work supporting portion 70 underlying the belt 42. To one end of the portion 70 there is welded a work stop 72 which is a U-shaped member having one leg 74 overlying the belt 42 with a lower leg 76 underlying the belt. When a work piece is pressed against the belt 42 within the area of the backing plate 70, the leg 74 serves as a stop to prevent the work being drawn with the belt into the casing member 80.

A similar casing member '82 guards the top portion of the pulley 30. Guards 80 and 82 are integral parts of a back guard 84 which, as shown in FIGURE 4, overlies most of one side of the machine and is rigidified by strengthening ribs 86. The guard as a whole is bolted at spaced points 88' in the frame 10. A strengthening strip 90 is riveted at one end 92 to the portion 80 and is bolted at the other end 94 to the frame of the motor 16. Member 90 is lightly riveted at 92 to the guard 80 so as to permit a slight pivoting of the member 90'. The bolt 94, securing the member 90 to the motor 16, engages an open slot in the member 90 While the bolts 88, securing the member 84 to the frame 10, are similarly engaged in open slots. When it is desired to change a belt, bolts 88 and 94 simply are loosened so the entire member 84 with guards 80 and 82 may be quickly disengaged from the machine so as to permit replacement of the belt.

In replacing the belt, the member 26 is drawn back against the spring 40 so as to relieve tension on the belt and permit easy removal and replacement. While this can be done simply by grasping and pulling on the member 26, in many cases the task will be simplified by the use of the handle shown in FIGURE 5. The handle 150 is made up of a plate 152 having an upper tongue 154 bent into hook formation and a pair of tongues 156 and 158 which are oppositely bent out of the plate 152 to form a trough opposing the hook 154. An elongated handle 160 is welded to the plate 152 and has, near its free end, a bent lug 162 for engagement with a ratchet 164 secured to the base 10. The hook 154 and trough 156-158 are engaged with the leg 26, as shown in FIGURE 2. Downward pressure on the handle 160 draws the leg 26 toward the driving pulley 18 to release tension on the belt 42. The lug 162 then is engaged with the ratchet 164 to hold the handle 160 down. When the belt 42 is replaced, the lug 162 is disengaged, and tension on the belt is restored. If desired, the plate 152, without the lugs 154-158 may be permanently welded to the leg 26.

It is doubtful whether any two belts, even of the same type, size and manufacture, will run precisely the same on any given pair of pulleys. For this reason, means are provided for easy adjustment to bring the belt into true running condition, that is, so that the belt will run smoothly without lateral deviations. To do this, the following mechanism is provided.

An arm 100 is welded to the plate 38 on which the brackets 24 are mounted. The plate 38 is secured to the base by means of a single bolt 102 and is, therefore, pivotal. At its free end, the member 100 is pivotally engaged by a rod 104 which passes freely through bearing members 106 and 108 welded to the base 10 and has threaded engagement with knurled knob 110 secured to the opposite end of the rod 104 and, when turned, moves the rod 104 axially backward and forward with resultant pivoting, by means of the member 100, of the plate 38. This serves to provide an angular adjustment of the axis of the pulley 32 so that almost instantaneously any newly applied belt can be brought into proper running condition.

Bracket 120 is welded to the base 10 and by means of a stud 122 is pivoted to an arm 124 which, at its opposite end, is pivoted to an arm 126 which in turn is pivoted to alight fixture 128. This provides universal adjustability for the light 128 relative to work presented either to the tool holder 52 or to the work support 70. A cable 130 is used to plug the machine into a suitable outlet and the cable enters a junction box 132 which is provided with an on-oif switch 134 for starting and stopping the motor 16 and is also provided with an ordinary plug-in socket 136 to receive a plug 138 which connects the lamp 128 to the power supply. Preferably, the junction box is arranged so that it the plug 138 is in place, as shown in FIGURE 1, the lamp will go on when the machine is plugged in. This is a feature of safety and convenience and serves as a positive indication that the motor is ready to operate.

While certain structural details have been disclosed and discussed in connection with this application, it is very clear that numerous structural changes will suggest themselves to those skilled in the art. For this reason, it is not intended to limit this invention to the precise details disclosed herein but only as set forth in the subjoined claims.

What is claimed is:

1. In a belt-type sander having a driving pulley and a driven pulley with the drive pulley journaled on a fixed base and the driven pulley on a mounting such that its axle is pivoted to swing about an axis parallel to said base and also pivoted to turn about an axis normal to said base, the improvement comprising a rod slidably mounted relative to said base, said rod having one end pivotally engaging said driven pulley mounting and its opposite end threaded into a turnable handle whereby turning said handle will shift said rod axially to adjust said mounting about said vertical axis.

2. A belt-type sander as set forth in claim 1, including resilient means on said mounting for biasing said driven pulley away from said driving pulley.

3. A belt-type sander as set forth in claim 2, in which said resilient means comprises a coiled spring having its coil anchored on said mounting with one end bearing on said mounting and the other end bearing on said driven pulley axle.

4. A belt-type sander as set forth in claim 2, including a handle mountable on said mounting to oppose said biasing means whereby to relieve tension on a sander belt.

5. A belt-type sander as set forth in claim 4, including means to retain said handle in belt tension relieving condition.

6. A belt-type sander as set forth in claim 1, including a single guard plate covering one side of said pulleys and the top of said pulleys while exposing a portion of a sanding belt running flat between said pulleys and exposing another portion of said belt on the surface of said drive pulley.

References Cited UNITED STATES PATENTS 2,893,176 7/1959 Bruck 5l170.4 3,312,116 4/ 1967 Blevins 51l70.4 X

FOREIGN PATENTS 555,382 4/1958 Canada.

OTHELL M. SIMPSON, Primary Examiner U.S. Cl. X.R. 57148 

